Tank bleeder



April 26, 1960 A. E. CROW 2,934,087

TANK BLEEDER Original Filed May 19, 1952 mvsmon Anos E. C'eow ATTORNEYUnited States Patent TANK BLEEDER Amos E. Crow, Long Beach, Calif.

Original application May 19, 1952, Seriai No. 288,685, now Patent No.2,732,071, dated January 24, 1956. Divided and this application January12, 1956, Serial No. 558,800

3 Claims. (Cl. 137-590) The present invention relates generally to thestorage of liquids within tanks, and more particularly to a novel tankbleeder for use with liquid storage tanks.

This application is a division of my application Serial No. 288,685entitled Tank Bleeder, filed in the Patent Oflice on May 19, 1952, whichissued on January 24, 1956, as Patent No. 2, 732,071.

Liquid storage tanks are widely used throughout the world today. In manyinstances it is necessary to store a plurality of liquids havingdifierent specific gravities in a single storage tank whereby suchliquids will assume separate horizontal stratums. A common exampleoccurs where oil or other hydro-carbon is stored in a tank together withwater, which water may have entered the tank with the oil or perhapslater entered the tank by means of leakage or condensation. Inasmuch assuch water will have a greater specific gravity than the oil it willsettle to the lower part of the tank in the form of a. strata.Thereafter, at such time as it becomes desirable to remove the oil fromthe tank this strata of water must be bled oil, whereafter substantiallyuncontaminated oil will remain for withdrawal.

The means heretofore proposed for bleeding off such water has generallycomprised a selectively-openable outlet of a comparatively smalldiameter located near the bottom of the tank. Occasionally, a horizontalpipe of the same diameter as such outlet may be inserted therethrough soas to draw water from a position spaced inwardly from the side of thetank wherein the outlet is formed. With either of these arrangements,unsatisfactory results are obtained inasmuch as considerable turbulenceis developed by water entering the small diameter outlet or pipe. Suchturbulence eflects an intermixing of the oil disposed above the waterwith the water being bl d from the tank, whereby a certain amount ofthis intermixed oil is bled ofi together with the water. in this mannera considerable amount of oil may be lost. However, it is true that suchoil which is bled off with the water may be later recovered by aresettling process or the like, but such process involves an appreciableamount of time and trouble and hence is to be avoided.

It is possible to avoid such turbulence and its consequent intermixingof oil with the water being bled oil by permitting the water to bleedofi at a very slow rate. The slow Withdrawal rate, however, is generallyobjectionable, primarily because an operator must stand by during thebleeding operation in order that he may close the outlet valve themoment the oil begins to drain from the tank. Accordingly, it isimportant that the bleeding oil be accomplished as quickly as possiblewhereby the operator may leave the tank and attend to his other duties.A slow withdrawal rate is also objectionable inasmuch as it prevents theimmediate re-use of the storage tank with a new body of oil.

It is a major object of the present invention to provide a tank bleederfor storage tanks which permits a tank to be bled in a minimum amount oftime and with a minimum amount of turbulence.

It is a further object of the present invention to provide a tankbleeder for storage tanks which is simple of design and rugged ofconstruction, whereby it may have a long and trouble-free service life.

It is another object of the present invention to provide a tank bleederfor storage tanks which maybe made from readily obtainable materials andby simple manufactoring processes whereby it may be sold at a low price.

An additional object of the present invention is to provide a tankbleeder for storage tanks which has a novel arrangement for returningany liquid of a lower specific gravity than that being bled oil whichinadvertently enters the bleeder to return to the main body of suchlighter liquid.

Other objects and advantages of the present invention will becomeapparent from the following detailed description thereof when taken inconjunction with the appended drawings wherein:

The single figure is a side elevational view of the invention.

Referring to the drawing, the lower portion of a storage tank designatedgenerally by the numeral 10 is shown that includes a bottom 12 in whichan opening 14 is formed through which a liquid outlet pipe 26a extendsupwardly. An oil and water mixture when discharged into tank 10 willgradually separate into two strata, the lower strata being water, andthe upper strata oil. The present invention permits the water to bedischarged from drain line 25a without any appreciable quantity of oilbeing discharged therewith as will be hereinafter explained in detail.

The invention 14a includes a circular metal base 16 having a centralopening 18 formed therein through which drain line 26a extends upwardly,with the drain line being welded or otherwise aflixed to the portion ofthe base adjacent opening 18. The base rests on the bottom 12.

A number of circumferentially spaced first stud bolts 30 projectupwardly from the upper peripheral edge of base 16. Also a number ofcircumferentially spaced stud bolts 32 of greater height than bolts 30extend upwardly from base 16. Bolts 32 are relatively close to the.upwardly projecting end portion of liquid outlet pipe 265:.

Stud bolts 30 have tubular spacers 34 disposed thereon, the lower endsof which rest on the upper surface of base 16. Spacers 34 terminatesubstantial distances below the upper ends of bolts 39. Likewise, bolts32 have tubular spacers 38 mounted thereon that rest on base 16 andterminate substantial distances below the upper ends of the bolts.

A frusto-conical turbulence shield 22a is provided that includes aring-shaped flange 40 in which a number of circumferentially spacedbores 42 are formed through which the upper end portions of bolts 30extend, with the flange being supported on the upper ends of spacers 34.The upper end portions of bolts 30 are threadedly engaged by nuts 44 toremovably support the flange in a fixed position relative to base 16. Afrusto-conical side wall 48 extends upwardly and inwardly from the innerperipheral edge of flange 40 and terminates in a first flat circularplate 50. A number of circumferentially spaced bores 52 are formed inplate through which the upper ends of bolts 32 extend. Side wall 48 hasa number of apertures 54 formed therein, the purpose of which will beexplained hereinafter.

A frusto-conical sheet metal collector 20a includes an upwardly andinwardly tapering side wall 56 that has an upwardly and outwardlytapered lip 58 extending around the lower peripheral edge portionthereof. Side Wall 56 terminates in a second circular plate 60 that hasa number of circumferentially spaced-bores 64 formed therein throughwhich the upper ends of bolts 32 extend. Plate 60 rests on the. uppereudsoi spacers 2,8. The upper sur-v cated by'the arrows. inthe drawing,Thereafter,

water will by gravity flow out of the tank through outlet pipe 26a.During the bleeding off of the water there w be t e t any tu i le s ecre te by the en ryo th a r n o t e co lecto -29- Tlt s esnltsimm thestreamlining nact ci a ifito i ed ua nj he' a s n of the col ec o l thee n s me t b en -s ould o ur w er, her by a ma l an i y of; Oil s ul bedrawn towards the large end of the oolleotor, the mai p t on of s h o li l Pa pwardly int t annular space separating the inside of theturbulence shield 22:: and the exterior of the collector 20 2. From herethe oil is free to pass through a plurality of apertures '54 formedabout the upper portion of the turbulence shield .22. Inasmuch as theoil will'be lighter than the water, such oil as may pass through theseapertures is and ur ulen e h el that dati g a lu a i y t openin s freeto return upwardly to the main body of oil (not 7 shown).

Although there have been described what is at present considered to bethe preferred forms of tank'bleeders embodying the present invention, itwill be apparent to those skilled in the art that various modificationsand changes may be made thereto without departing from the spirit of theinvention or the scope of the appended claims.

I claim:

l. A tank bleederfor usein separating and drawingoif two layers ofliquids differing in specific gravity from a tank due to the hydraulichead to which the lowermost layer is subjected, including:, an outletpipe having a generally vertical open-ended portion that extends up.-wardly'from the bottom-part of said tank;;a frusto-conical turbulenceshield, the central portion of which is positionedabove the upperextremity of said pipe and ms posed in a substantially horizontal plane,said shield having a continuous side wi hin which a plurality ofapertures are formed; a horizontally disposed plate proecting outwardlyfrom said vertical portion of'saicl pipe, sald plate extendingbeneathsaid turbulence shield and being vertically spaced therefrom; aplurality'of circumy and hold said plate and shield in said spacedrelationship,

with the total area of said openings being such that fluid can flowtherethrough without appreciable turbulence at the maximum rate saidfluid can be discharged from said outlet pipe when said liquid tobeseparated is subjected to the maximum hydraulie headpossible in saidtank; a frusto-conical collector situated within, said turbulenceshield, with the central portion of said collector being positionedabove the upper extremity of said outlet pipe, said collector beingfo-rmed with a continuous side wall disposed at a lesser angle tothevertical than that or the side wall of said shield to define anannulus-shaped space therebetween with the lower horizontal edge of saidcollector terminating, inte'rmediately between the lower extremity ofsaid shield and the upper surface of said base plate; and means forholding said collector and turbulence shield infixed relationship topermit separation of said iqu alter en n aid peni into, a fi t mo nstream flowing into said annulus-shaped SPE SE, and a second morerapidly moving stream flowing upwardly inside said collector todischarge into said pipe with the relative rate of flow of said streamsbeing determined by thetotal area of saidapertures and the area of saidopenings, which area ratio is such that portions of said upper liquidlayer inadvertently mixed with said lower liquid layer as it enters saidbleeder will be directed, due to its natural tendency to rise into saidfirst stream and continue said rise as said first stream flows throughsaid apertures to return to the main body of said upper layer.

2. A tank bleeder as defined in claim 1 wherein said collector andturbulence shield are formed with flat central portions that abutagainst one another.

3.; A tank bleeder as defined in claim 1 wherein said holding meansinclude a plurality of circumferentiallY 548,215 Montgomery Oct. 22,1895 571,278 McCaWley l Nov. 10, 1896 833,150 Attenhofer Oct. 16, 19061,054,004 7 La Croix Feb. 25, 1913 1,716,544 Felted June 11, 19291,945,824 Saxe Feb. 6, 1934

